feat: migrate from Cedar to SpiceDB authorization system

This is a major architectural change that replaces the Cedar policy-based
authorization system with SpiceDB's relation-based authorization.

Key changes:

- Migrate from Rust to Go implementation
- Replace Cedar policies with SpiceDB schema and relationships
- Switch from envoy `ext_authz` with Cedar to SpiceDB permission checks
- Update build system and dependencies for Go ecosystem
- Maintain Envoy integration for external authorization

This change enables more flexible permission modeling through SpiceDB's
Google Zanzibar inspired relation-based system, supporting complex
hierarchical permissions that were difficult to express in Cedar.

Breaking change: Existing Cedar policies and Rust-based configuration
will no longer work and need to be migrated to SpiceDB schema.

1 files changed, 78 insertions, 0 deletions

diff --git a/vendor/github.com/google/yamlfmt/feature.go b/vendor/github.com/google/yamlfmt/feature.go
new file mode 100644
index 00000000..af56dda1
--- /dev/null
+++ b/vendor/github.com/google/yamlfmt/feature.go
@@ -0,0 +1,78 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package yamlfmt
+
+import (
+	"context"
+	"fmt"
+)
+
+type FeatureFunc func(context.Context, []byte) (context.Context, []byte, error)
+
+type Feature struct {
+	Name         string
+	BeforeAction FeatureFunc
+	AfterAction  FeatureFunc
+}
+
+type FeatureList []Feature
+
+type FeatureApplyMode string
+
+var (
+	FeatureApplyBefore FeatureApplyMode = "Before"
+	FeatureApplyAfter  FeatureApplyMode = "After"
+)
+
+type FeatureApplyError struct {
+	err         error
+	featureName string
+	mode        FeatureApplyMode
+}
+
+func (e *FeatureApplyError) Error() string {
+	return fmt.Sprintf("Feature %s %sAction failed with error: %v", e.featureName, e.mode, e.err)
+}
+
+func (e *FeatureApplyError) Unwrap() error {
+	return e.err
+}
+
+func (fl FeatureList) ApplyFeatures(ctx context.Context, input []byte, mode FeatureApplyMode) (context.Context, []byte, error) {
+	// Declare err here so the result variable doesn't get shadowed in the loop
+	var err error
+	result := make([]byte, len(input))
+	copy(result, input)
+	for _, feature := range fl {
+		if mode == FeatureApplyBefore {
+			if feature.BeforeAction != nil {
+				ctx, result, err = feature.BeforeAction(ctx, result)
+			}
+		} else {
+			if feature.AfterAction != nil {
+				ctx, result, err = feature.AfterAction(ctx, result)
+			}
+		}
+
+		if err != nil {
+			return ctx, nil, &FeatureApplyError{
+				err:         err,
+				featureName: feature.Name,
+				mode:        mode,
+			}
+		}
+	}
+	return ctx, result, nil
+}